Electrophotographic light-sensitive element

Abstract

An electrophotographic light-sensitive element which is useful in the Carlson electrophotographic process is disclosed, comprising an electrically conductive support having provided thereon a photoconductive layer and a protective layer wherein said protective layer has a thickness of from 1 to 30 μm and contains a powder of a metal oxide having a volume intrinsic resistance of 10 11 Ω·cm or less and a mean particle size of 0.3 μm or less dispersed in a binder resin.

What is claimed is: 
     
       1. An electrophotographic light-sensitive element comprising an electrically conductive support having provided thereon, in sequence, a photoconductive layer and a protective layer, wherein said protective layer has a thickness of from 1 to 30 μm and contains a powder of a metal oxide having a volume intrinsic resistance of 10 11  Ω·cm or less in an amount of from 10 to 40% by weight based on the total weight of the protective layer and a mean particle size of 0.3 μm or less dispersed in a binder resin, said protective layer being substantially transparent in wavelength regions of light to which said photoconductive layer is sensitive. 
     
     
       2. An electrophotographic light-sensitive element as in claim 1, wherein said protective layer is substantially transparent to light in the wavelength of from about 0.45μ to about 0.72μ. 
     
     
       3. An electrophotographic light-sensitive element comprising an electrically conductive support having provided thereon, in sequence, a photoconductive layer, a barrier layer and a protecitve layer, wherein said protective layer has a thickness of from 1 to 30 μm and contains a powder of a metal oxide having a volume intrinsic resistance of 10 11  Ω·cm or less and a mean particle size of 0.3 μm or less dispersed in a binder resin, said protective layer being substantially transparent in wavelength regions of light to which said photoconductive layer is sensitive, wherein said barrier layer has a higher electric resistance than said protective layer. 
     
     
       4. An electrophotographic light sensitive-element as in claim 1 or 3, wherein said metal oxide is selected from the group consisting of zinc oxide, titanium oxide, tin oxide, bismuth oxide, indium oxide, and antimony oxide. 
     
     
       5. An electrophotographic light-sensitive element as in claim 1 or 3, wherein said powder has a mean particle size of 0.15 μm or less. 
     
     
       6. An electrophotographic light-sensitive element as in claim 1 or 3, wherein said binder resin is selected from the group consisting of polyester resins, polycarbonate resins, polyurethane resins, epoxy resins, acryl resins, vinyl chloride-vinyl acetate copolymers, silicone resins, alkyd resins, polyvinyl chloride resins, cyclic butadiene rubbers, and fluorocarbon resins. 
     
     
       7. An electrophotographic light-sensitive element as in claim 6, wherein said binder resin is a polyurethane resin. 
     
     
       8. An electrophotographic light-sensitive element as in claim 1 or 3, wherein the thickness of said protective layer is from 3 to 15 μm. 
     
     
       9. An electrophotographic light-sensitive element as in claim 1 or 3, wherein said protective layer has an intrinsic resistance of from 10 13  Ω·cm to 10 11  Ω·cm. 
     
     
       10. An electrophotographic light-sensitive element as in claim 1 or 3, wherein said powder has a mean particle size of 0.10 μm or less. 
     
     
       11. An electrophotographic light-sensitive element as in claim 3, wherein said powder is present in an amount of from 10 to 40% by weight based on the total weight of the protective layer. 
     
     
       12. An electrophotographic light-sensitive element as in claim 3, wherein said protective layer is substantially transparent to light in the wavelength of from about 0.45μ to about 0.72μ. 
     
     
       13. An electrophotographic light-sensitive element comprising an electrically conductive support having provided thereon, in sequence, a photoconductive layer and a protective layer, wherein said protective layer has a thickness of from 1 to 30 μm and contains a powder of a metal oxide having a volume intrinsic resistance of 10 11  Ω·cm or less dispersed in a binder resin, said protective layer being substantially transparent in wavelength regions of light to which said photoconductive layer is sensitive and said powder consisting essentially of tin oxide and antimony oxide in the form of a single powder having a mean particle size of 0.15 μm or less. 
     
     
       14. An electrophotographic light sensitive element as in claim 13, wherein the weight ratio of tin oxide/antimony oxide in said powder is in the range of from 98/2 to 70/30. 
     
     
       15. An electrophotographic light-sensitive element as in claim 13, wherein said powder is present in an amount of from 10 to 40% by weight based on the total weight of the protective layer. 
     
     
       16. An electrophotographic light-sensitive element as in claim 13, wherein said protective layer is substantially transparent to light in the wavelength of from about 0.45μ to about 0.72μ. 
     
     
       17. An electrophotographic light-sensitive element comprising an electrically conductive support having provided thereon, in sequence, a photoconductive layer, a barrier layer and a protective layer, wherein said protective layer has a thickness of from 1 to 30 μm and contains a powder of a metal oxide having a volume intrinsic resistance of 10 11  Ω·cm or less dispersed in a binder resin, said protective layer being substantially transparent in wavelength regions of light to which said photoconductive layer is sensitive and said powder consisting essentially of tin oxide and antimony oxide in the form of a single powder having a mean particle size of 0.15 μm or less and wherein said barrier layer has a higher electric resistance than the said protective layer. 
     
     
       18. An electrophotographic light-sensitive element as in claim 17, wherein said powder is present in an amount of from 10 to 40% by weight based on the total weight of the protective layer. 
     
     
       19. An electrophotographic light-sensitive element as in claim 17, wherein the weight ratio of tin oxide/antimony oxide in said powder is in the range of from 98/2 to 70/30. 
     
     
       20. An electrophotographic light-sensitive element as in claim 17, wherein said protective layer is substantially transparent to light in the wavelength of from about 0.45μ to about 0.72μ. 
     
     
       21. In an electrophotographic process for forming a electrostatic latent image on a light-sensitive element comprising an electrically conductive support having provided thereon, in sequence, a photoconductive layer and a protective layer, which comprises uniformly charging and image-wise exposing to light said element from the protective layer side, wherein said protective layer has a thickness of from 1 to 30 μm and contains a powder of a metal oxide having a volume intrinsic resistance of 10 11  Ω·cm or less in an amount of from 10 to 40% by weight based on the total weight of the protective layer and a mean particle size of 0.3 μm or less dispersed in a binder resin, said protective layer being substantially transparent in wavelength regions of light to which said photoconductive layer is sensitive.